The 38 provincial heads of the Anglican Communion meet next week in Northern Ireland for "careful study of the Windsor Report," the recommendations issued last October on the future of Anglican unity amid deep divisions over theology, ethics, and practice.

Anglicans and religion journalists, however, are getting tired. The resolution of each meeting of Anglican leaders seems to be, "just wait until the next meeting." Though some orthodox and conservative Anglicans are hopeful that leaders from southern provinces, especially in Africa, will stand firmly against North American theological liberalism and sexual libertinism, few are expecting anything decisive. This isn't being billed as the Anglican Council of Nicaea.

Not that the Council of Nicaea was as decisive as it is usually billed, either. It took almost 60 years for Nicaea's influence to solidify. In the meantime, the main heresy condemned at the council, Arianism, became ascendant and almost triumphed over orthodoxy. Even the Nicene Creed recited today wasn't really adopted until 381, 56 years after the council ended.

The Council of Nicaea was not, as Da Vinci Code novelist Dan Brown has convinced scores of readers, the place where the church made up the ideas of Jesus' divinity and the infallibility of Scripture, but it still stands as one of the biggest moments in church history (which is why Christian History & Biography has devoted its next issue to the council; click here if you don't already subscribe).

A fewAnglican leaders have made a habit of systematically denying each line of the Nicene Creed, but most Anglicans revere the council as authoritative. So it was no throwaway comment when the Windsor Report made direct reference to the council's canons (rules or standards) in issuing its evaluation. But the Lambeth Commission on Communion, which issued the Windsor Report, didn't invoke Nicaea to talk about heretical priests and bishops in the West. Instead, the canons appeared in a discussion of how some orthodox parishes have responded to their own apostate leaders by seeking outside oversight:

Some Archbishops from elsewhere in the Communion have, both by taking initiatives, and by responding to invitations from clergy purporting to place themselves under their jurisdictions, entered parts of the Episcopal Church (USA) and the Anglican Church of Canada and exercised episcopal functions without the consent of the relevant diocesan bishop. This goes not only against traditional and often-repeated Anglican practice … but also against some of the longest-standing regulations of the early undivided church (Canon 8 of Nicaea). These actions are not purely reactions to recent events, though that has been their main character. In some cases they build on earlier attempts at unilateral action against bishops whose theology and/or practice was perceived to be out of line with traditional Anglican and Christian teaching, or even to set up would-be "orthodox" structures or "mission churches" for their own sake, e.g. the Anglican Mission in America (AMiA).

Conservatives were aghast that the Lambeth Commission treated orthodox leaders offering "alternative oversight" as akin to blessing same-sex unions and ordaining actively homosexual bishops in terms of disrupting church unity. But even the evangelicals on the commission stood by the claim. Bishop of Durham N.T. Wright, whose orthodox credentials are impeccable, told Christianity Today:

The important thing to say is that border crossings are disruptive. Not only are they against the spirit and the letter of Anglican formularies, they are against one of the decrees of the Council of Nicaea, as we point out. And I think not a lot of people know this, but it's important to say this was a question that the early fathers faced at the same time as they were hammering out the doctrine of the person of Jesus Christ, and that they gave it their time to say people should not do this because that's not how episcopacy works.

Now, of course it's open to people to come back and say episcopacy has broken down because of this and this. But then the critical thing, and this is where it is very similar, is that we have mechanisms—they demand patience, of course, which many of us don't have in great supply.

The problem with the Windsor Report's reference to the canons of Nicaea, some conservatives have responded, is that it focuses on the wrong heretics.

The Arians, who denied the full divinity of Christ, were spotlighted at the Council of Nicaea, and most of the council's work focused on accurately defining Jesus' nature. But the 20 canons adopted, in addition to setting the date of Easter and regulating aspects of church life, deal with two other heretical groups.

The first are the Cathari, or Novatians. (This is the group referenced in the eighth canon, which the Windsor Report references.) While condemned as heretics, followers of Novatian were doctrinally orthodox. Novatian, in fact, had written one of the church's important works on the Trinity. This, then, was a group that could say the Nicene Creed with pride.

Indeed, pride was the issue: Novatians were outraged at how easily those who had lapsed under persecution had been received back into the church once the pressure lifted. They were also upset with lax church attitudes toward the twice-married. The solution, as they saw it, was to appoint rival bishops to "compromised" sees, which earned them a reputation as schismatics condemned by the rest of the church. At Nicaea, the Novatian bishop Acesius was personally criticized by Emperor Constantine, who had been more conciliatory with those who denied orthodox theology.

If a Novatian wanted to return to the church's good graces, the Council of Nicaea ruled, all they had to do was to "profess in writing that they will observe and follow the dogmas of the Catholic and Apostolic Church." Novatian priests could stay priests. Novatian bishops had to be under the local orthodox bishop, but in many cases didn't even have to step down in rank (whether a Novatian bishop retained the title of bishop or became a priest was up to the local orthodox bishop). It's important that the ex-Novatian "be evidently seen to be of the clergy," the Council decided, so long as "there may not be two bishops in the city."

Canon 8, however was markedly different from the other one dealing with heretics: Canon 19, which addressed the Paulianists. These followed the bishop of Antioch, Paul of Samosata, who was known both for heresy and an opulent lifestyle. He expressly rejected the deity of Christ, whom he considered an "ordinary man" inspired by the Word of God.

A Paulianist returning to orthodoxy had to do much more than simply offer a letter professing fealty to the church. "They must by all means be rebaptized," the council declared. Even clergy "found blameless and without reproach" had to go through ordination again. Clergy found unfit were deposed. Deaconesses were laicized. In short, they held a place between heretic and unbeliever. The church may have welcomed repentant Paulianists, but it was with a reluctant handshake, not with open arms.

So the question for today is applicability. Many orthodox Anglicans in the West see the Episcopal Church (USA) not just as wayward, but as apostate. Bishops who deny the authority of Scripture and declare that God has changed his mind on matters of sexual ethics, they say, are heretics, not just schismatics. The repentance of the Paulianists is in order, not the assurances of the Novatians. Anglican liberals may find parallels between Novatian rigors on remarriage and today's conservative emphasis on sexual ethics, but that doesn't mean that the Anglican Mission in America or other groups offering "alternative oversight" are schismatics, let alone heretics.

The Windsor Report misses the real lessons of Nicaea, says Robert J. Sanders, associate rector of St. Mark's Episcopal Church in Jacksonville, Florida, in an online commentary. He writes, "What does Nicaea teach us? It teaches us that believers need to come under the oversight of bishops, that they cannot receive from heretical bishops, and therefore, orthodox bishops must officiate in dioceses headed by heretical bishops."

The 49-page Windsor Report has enough mystery and controversy in it to keep the Primates busy during their meeting. There's a good chance that a parenthetical aside referencing the Council of Nicaea won't even come up. But one hopes that some lessons of Nicaea won't be lost on the Anglican Communion. In 325, church leaders were willing to die to see that orthodox doctrine was upheld. It didn't come to that: Instead, orthodox Christians, despite "winning" at Nicaea, had to face decades of uncertainty and apparent defeat before the church got its act together. Boldness and patience will likely be needed again among Anglicans.